MAINTENANCE SERVICE
GENERAL00-40
The temperature of the surface of the belt should be as
close as possible to underhood temperature.
Do not let any contaminants such as water or oil get
onto the microphone.
If strong gusts of wind blow against the microphone or
if there are any loud sources of noise nearby, the val-
ues measured by the microphone may not correspond
to actual values.
If the microphone is touching the belt while the mea-
surement is being made, the values measured by the
microphone may not correspond to actual values.
Do not take the measurement while the vehicle's engine
is running.
5. Hold special tool MB991668 (microphone) to the middle of
the drive belt between the pulleys (at the place indicated by
the arrow), about 10
20 mm (0.4 0.8 inch) away from the
rear surface of the belt and so that it is perpendicular to the
belt (within an angle of
15 degree angle).
6. Gently tap the middle of the belt between the pulleys (the
place indicated by the arrow) with your finger as shown in
the illustration, and check that the vibration frequency of the
belt is within the standard value.
Standard value:
NOTE: Because the frequency depends on the belt material,
confirm Part No. shown on the reverse of the belt.
.
Part No. Vibration frequency Hz
MD368275 133
158
MN158101, MN187016 143
169
